1. Field of the Invention
An assembly for shifting gear positions in an electronically controlled transmission including a single lever control for moving between various gear positions.
2. Description of the Prior Art
Such assemblies typically include a shift lever pivotally mounted to a support for movement between a plurality of gear positions. The gear positions are established by a plurality of detent valleys. Each of the detent valleys corresponds to one of the gear positions such as park, reverse, neutral or drive. The use of detent valleys provides the operator with the feel of locking the shift lever into a gear position. The shift lever is held into the detent valley by a locking mechanism. The typical assemblies utilize a push button located at the top of the shift lever to release the locking mechanism and allow the shift lever to move to another gear position.
The assemblies also include a plurality of sensors that are used to detect the selected gear position of the shift lever. A common type of sensor used for this type of assembly is a Hall effect sensor. The Hall effect sensors generate an output voltage as the result of close proximity with a magnetic field. A plurality of magnets is used to generate the magnetic field necessary to activate the Hall effect sensors.
Examples of such assemblies are shown in U.S. Pat. No. 4,489,303 to Martin; U.S. Pat. No. 4,610,179 to Parker; U.S. Pat. No. 4,660,430 to Bortfeld; U.S. Pat. No. 5,406,860 to Easton; U.S. Pat. No. 5,775,165 to Lu. These assemblies include the use of detent valleys and Hall effect sensors to control the selection of gear positions within an electronically controlled transmission. These same assemblies use magnets to activate the sensors. Often there are several magnets used to activate several different Hall effect sensors at the same time. The activation of a specific combination of the Hall effect sensors generates the shifting of gear positions in the electronically controlled transmission.
These assemblies require a plurality of magnets and Hall effects sensors. The increased number of magnets and sensors increases the weight, size and cost of the assemblies. It would be desirable to have a shift lever assembly to control an electronically controlled transmission that would provide an operator with the feel of locking into the selected gear position while using fewer components.
The present invention provides single lever shift assembly for changing gear positions of an electronically controlled transmission comprising a column support or a base with two gates to support a shift lever. The shift lever is used to move between a plurality of gear positions. For a column shift assembly the shift lever is mounted to the column support at an end attachment of a terminal shaft. The assembly contains a plurality of detent valleys with each of the detent valleys corresponding to one of the gear positions. A detent finger mechanism is biased into the detent valleys. A plurality of sensors, for detecting the selected gear positions of the shift lever, is disposed in the detent valleys. A magnet supported by the detent finger mechanism activates the sensors to alert the electronically controlled transmission of the selected gear position.
An advantage of the present invention is that the shift lever moves between the plurality of gear positions without the use of a push button locking mechanism. The detent valleys provide a peak on each side that provides a lock for the shift lever. The peaks prevent the shift lever from inadvertently slipping into another gear position. Therefore, the use of detent valleys eliminate the need for a push button locking mechanism, thus reducing the number of components and the cost of the shift lever assembly.